74HCT4046ADB NXP Semiconductors, 74HCT4046ADB Datasheet - Page 25

• Manufacturer Part Number: 74HCT4046ADB
• Description: Phase Locked Loops (PLL) PHASE LOCKED LOOP W/VCO
• Manufacturer: NXP Semiconductors
• Type: PLLr

Specifications of 74HCT4046ADB

• Number Of Circuits: 1
• Supply Voltage (max): 5.5 V
• Supply Voltage (min): 4.5 V
• Maximum Operating Temperature: + 125 C
• Minimum Operating Temperature: - 40 C
• Mounting Style: SMD/SMT
• Operating Supply Voltage: 4.5 V to 5.5 V
• Package / Case: SSOP-16
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 74HCT4046ADB,112

Philips Semiconductors
APPLICATION INFORMATION
This information is a guide for the approximation of values of external components to be used with the 74HC/HCT4046A
in a phase-lock-loop system.
References should be made to Figs 29, 30 and 31 as indicated in the table.
Values of the selected components should be within the following ranges:
R1
R2
R1 + R2 parallel value
C1
1997 Nov 25
SUBJECT
VCO frequency
without extra
offset
Phase-locked-loop with VCO
between 3 k and 300 k ;
between 3 k and 300 k ;
greater than 40 pF.
PHASE
COMPARATOR
PC1, PC2 or PC3
PC1
PC2 or PC3
2.7 k ;
DESIGN CONSIDERATIONS
VCO frequency characteristic
With R2 =
characteristics of the VCO operation will be as shown in Fig.25.
(Due to R1, C1 time constant a small offset remains when R2 = .).
Fig.25 Frequency characteristic of VCO operating without offset:
f
Selection of R1 and C1
Given f
Given f
Fig.31 to obtain 2f
0
= centre frequency; 2f
max
o
, determine the values of R1 and C1 using Fig.29.
and f
25
and R1 within the range 3 k
o
, determine the values of R1 and C1 using Fig.29, use
L
and then use this to calculate f
L
= frequency lock range.
74HC/HCT4046A
R1
300 k , the
min
Product specification
.